Major amputation compared with graft occlusion as the end point for assessing results of bypass surgery in lower limb ischaemia

Risk factors for autogenous infrainguinal bypass occlusion in patients with prosthetic inflow grafts

OBJECTIVE

In patients with prosthetic inflow (PI) grafts the proximal anastomosis of autogenous infrainguinal bypass (AIB) can be placed on the PI or on a distal native vessel in the groin. This study was performed to determine the effect of placement of an AIB proximal anastomotic site in a patient with ipsilateral PI.

METHODS

Patients undergoing AIB and PI between January 1990 and July 2002 were included in the study. They were classified into two groups on the basis of location of the proximal anastomosis. In group 1 the AIB proximal anastomosis was placed on the PI in the groin, whereas in group 2 the AIB proximal anastomosis was placed on a distal native groin artery. Patency, limb salvage, and patient survival in the two groups were calculated with the Kaplan-Meier method. The Cox proportional hazards model was used to determine independent risk factors affecting AIB patency.

RESULTS

Two hundred twenty-nine patients underwent AIB and PI. In group 1, 23 AIBs became thrombosed concurrent with 26 PI occlusions, and in group 2, 7 AIBs became thrombosed concurrent with 36 PI occlusions (P <.001). Five-year assisted primary patency, limb salvage, and patient survival in groups 1 and 2 were 50% and 75% (P <.001, log-rank test), 78% and 90% (P =.005, log-rank test), and 56% and 69% (P = NS, log-rank test), respectively. Factors independently associated with AIB occlusion are hypertension (hazard ratio [HR], 3.41; 95% confidence interval [CI], 1.65-7.05; P =.001), postoperative warfarin sodium therapy (HR, 1.86; 95% CI, 1.07-3.23; P =.03), continued smoking (HR, 1.72; 95% CI, 0.93-3.18; P =.08), AIB arising from PI (HR, 2.38; 95% CI, 1.35-4.18; P =.003), and PI occlusion (HR, 3.70; 95% CI, 2.15-6.36; P <.001).

CONCLUSION

A proximal AIB anastomosis located directly on the PI is an independent risk factor for decreased AIB patency of equal or greater importance than current smoking, hypertension, or PI occlusion. The proximal anastomosis of an AIB in a patient with an ipsilateral PI should be placed on a distal native artery.

Long-term functional status and quality of life after lower extremity revascularization

OBJECTIVE

The objective of this study was to assess the longer term (up to 7 years) functional status and quality of life outcomes from lower extremity revascularization.

METHODS

This study was designed as a cross-sectional telephone survey and chart review at the University of Minnesota Hospital. The subjects were patients who underwent their first lower extremity revascularization procedure or a primary amputation for vascular disease between January 1, 1989, and January 31, 1995, who had granted consent or had died. The main outcome measures were ability to walk, SF-36 physical function, SF-12, subsequent amputation, and death.

RESULTS

The medical records for all 329 subjects were reviewed after the qualifying procedures for details of the primary procedure (62.6% arterial bypass graft, 36.8% angioplasty, 0.6% atherectomy), comorbidities (64% diabetics), severity of disease, and other vascular risk factors. All 166 patients who were living were surveyed by telephone between June and August 1996. At 7 years after the qualifying procedure, 73% of the patients who were alive still had the qualifying limb, although 63% of the patients had died. Overall, at the time of the follow-up examination (1 to 7.5 years after the qualifying procedure), 65% of the patients who were living were able to walk independently and 43% had little or no limitation in walking several blocks. In a multiple regression model, patients with diabetes and patients who were older were less likely to be able to walk at follow-up examination and had a worse functional status on the SF-36 and a lower physical health on the SF-12. Number of years since the procedure was not a predictor in any of the analyses.

CONCLUSION

Although the long-term mortality rate is high in the population that undergoes lower limb revascularization, the survivors are likely to retain their limb over time and have good functional status.

Effect of perioperative blood transfusions on recurrence of colorectal cancer: meta-analysis stratified on risk factors

PURPOSE

This study was undertaken to evaluate the influence of perioperative blood transfusions on colorectal cancer recurrence.

METHODS

All articles published up to December 1996 in English (or with an English abstract) were retrieved, both using MEDLINE and scanning their references, to be considered for this meta-analysis.

RESULTS

One hundred thirty-one articles were identified, and 99 of them were excluded because they analyzed survival or mortality, were repetitive publications, or were reviews or letters. Thirty-two original studies (9 were prospective) on 11,071 patients were included for further analysis; 20 showed a detrimental effect of perioperative blood transfusions. Nineteen articles used also multivariable techniques, and 11 found perioperative blood transfusions to be an independent prognostic factor. Pooled estimates of the effect of perioperative blood transfusions on colorectal cancer recurrence yielded an overall odds ratio of 1.68 (95 percent confidence interval, 1.54-1.83) and a rate difference of 0.13 (95 percent confidence interval, 0.09-0.17) against patients who received transfusions. Stratified meta-analyses also confirmed these findings when stratifying patients by site and stage of disease. The effect of perioperative blood transfusion was observed in a dose-related fashion, regardless of timing and type, although some heterogeneity was detected. Data on surgical techniques were not available for further analysis.

CONCLUSIONS

A consistently detrimental association was discovered between the use of perioperative blood transfusion and colorectal cancer recurrence. Further studies are needed to confirm that blood transfusion has a causal association.

The status of lower-limb amputation in Bangladesh: a 6-year review

We conducted a review of 450 single lower-limb amputations performed in our hospital in Bangladesh between July 1982 and June 1987. The incidence of amputation in the specific area of 1000000 inhabitants covered by the hospital was 0.75/10(3) per year. The indications for amputation were: limb ischemia in 366 patients (81%), traumatic crush injury in 45 (10%), diabetes-associated complications in 20 (5%), severe limb infection in 10 (2%), and neoplasm growth in 10 (2%). The ratio of above-knee (AK) to below-knee (BK) amputation was 1:65, and 36 patients (8%) required reamputation, 22 of whom had undergone BK amputation previously. Thus, the number of patients with a final amputation at AK level was 302 (67%). The operative mortality was 21% and the uncomplicated primary wound healing rate was 89% within the survivors. Among the 355 patients who survived the amputation, 265 (75%) were given a prosthesis, 50 (14%) refused a prosthesis, and the remaining 40 (11%) were unfit for a prosthesis. Rehabilitation was successful in 44% of the AK and 86% of the BK amputees. In conclusion, when amputation is inevitable, maximum consideration should be given to the type of surgery performed to avoid rehabilitation failure.

Angioplasty gives good results in critical lower limb ischaemia. A 5-year follow-up in patients with known ankle pressure and diabetic status having femoropopliteal dilations

137 consecutive patients with known ankle pressures and diabetic status had attempted femoro-popliteal dilatation for lower limb ischaemia in an English provincial teaching hospital. All except one were followed until failure or death to assess survival and amputation rates. Non-diabetic patients with critical limb ischaemia had a 5 year survival rate of 62.2% (SE 17.1) compared to 50.5% (SE 7.0) for claudicants, with no significant difference on logrank testing. Diabetics had a relative risk of amputation of 11.2 compared to nondiabetics. Patients with pre-treatment ankle pressures of 50 mm or less had a relative risk of amputation of 2.6 compared to those with higher resting pressures. It is concluded that angioplasty should be the treatment of first choice in critical lower limb ischaemia whenever it is technically possible. Including patients with rest pain in the critical ischaemia group does not significantly affect cumulative patency rates.

The Immunosuppressive Aspects of Blood Transfusion

Blood transfusion is associated with immunosuppression, although the exact etiology of the immunosuppressive effect is not fully understood. The clinical significance of the immunosuppressive effect of blood transfusion has been examined in three situations: (1) studies of renal allograft survival after renal transplantation, (2) outcome studies in patients who have had surgical resection of solid cancer tumors, and (3) studies of infection rates in postoperative patients. In each scenario, the data support the conclusion that transfusion is associated with immunosuppression as manifested by increased renal allograft survival, increased recurrence and mortality rates in patients with cancer, and increased infection rates in postoperative patients who are transfused. Not all studies demonstrate an immunosuppressive effect of transfusion. There are several possible explanations for these discrepancies. First, prognostic variables other than transfusion itself account for the outcome results in these retrospective studies. Second, the extent of immunosuppression may be influenced by the type of blood product transfused, the amount transfused, and the timing of the transfusion; these factors have not been considered in all studies. For example, whole blood has been implicated as having a greater immunosuppressive effect than packed red blood cells, and many studies have shown that more than three units of packed red blood cells are necessary to affect outcome. Controlled animal studies have tested the hypothesis that transfusions increase solid tumor growth or the risk for infection. These studies have yielded conflicting results. Nevertheless, evidence that blood transfusion influences clinical outcome mitigates that a decision to transfuse must consider both risks and benefits of a transfusion; the possible consequences of immunosuppression must be included among the risks. Use of autologous blood, erythropoietin, and, in the future, synthetic hemoglobin may lead to improved outcome in patients with certain disease processes.

Perioperative blood transfusion and gastric cancer: adverse effects or unfavourable conditions of pretreatment?

The use of perioperative blood transfusion (PBT), the immunological status pre-operatively and at discharge from hospital, and the clinical course were examined retrospectively in 124 patients who underwent 'curative' resection for gastric cancer at Shinkokura Hospital, Japan from 1979 to 1988. The general condition of patients with PBT was worse than that of those without PBT and the pre-operative immunological status of patients with PBT was less favourable than that of those without PBT. At the time of discharge from hospital the immunological condition remained worse for patients who had been given PBT. The clinical course of patients with PBT was significantly worse. A dose-response relationship was evident but the types of blood products did not influence the outcome. Cox regression analysis adjusting for potentially confounding prognostic factors revealed that the clinical course was not altered by perioperative blood transfusion itself. These observations do not support the idea of adverse effects of perioperative blood transfusion on outcome of patients undergoing 'curative' resection for gastric cancer.

Influence of blood transfusion on recurrence, survival and postoperative infections of laryngeal cancer

Clinical and experimental studies indicate, that blood transfusion can modify the recipient's immune system. While beneficial to renal allograft survival, these immunomodulating effects may, however, prove detrimental to cancer patients. Recently, an adverse relationship between blood transfusion and cancer recurrence was reported in colon, lung, breast, kidney and gastric cancer. Moreover, a higher postoperative infection rate was observed when blood units were administered intraoperatively. We retrospectively reviewed the records of 174 patients with squamous cell carcinoma of the larynx undergoing curative resection between 1979 and 1985. One hundred and forty-one patients received blood transfusions, 33 did not. Recurrence rate (16.7%) was significantly related to clinical stage (p = 0.008) and lymph node status (p = 0.000); cumulative survival time depended significantly on clinical stage (p = 0.003), lymph node status (p = 0.004) and tumor size (p = 0.017). In contrast, when corrected for these baseline prognostic factors, no significant correlation could be detected between blood transfusion and cancer relapse. Also, survival time did not depend on blood transfusions. No correlation could be found between postoperative infection rate and intraoperative application of blood transfusion (p = 0.694). The present study does not support the hypothesis that blood transfusion adversely affects the prognosis of patients with laryngeal cancer. It indicates, that risk factors other than blood transfusion have a greater influence on recurrence and survival time.

Major amputation in a defined population: incidence, mortality and results of treatment

Medical records of all patients, from a defined population of 88,000 inhabitants, who underwent major lower limb amputation during 1980-82 were retrospectively scrutinized. The records showed 131 amputations were performed in 106 patients at the district hospital and 22 amputations on 17 patients at the local university hospital, referral centre, altogether 57 men and 66 women. This gave an amputation incidence of 46 per 10(5) inhabitants per year. Of the amputees 47 per cent were older than 80 years. Only two patients underwent reconstructive vascular surgery (at the university hospital) before surgery. Final amputation level was above-knee in 61 per cent of the patients treated at the district hospital. Mortality rates at 30 days and 2 years after the amputation were 23 and 56 per cent, respectively, and the age-corrected survival after 2 years was 55 per cent. For patients who came from and eventually returned to their own homes the mean hospital stay amounted to 184 days (postoperative deaths excluded). After amputation 26 patients were trained to wear a prosthesis and 16 of these used the prosthesis 2 years after amputation. The present study underlines the need for prospective and parallel studies of vascular surgery and amputation as well as analyses of the risk factors involved in lower limb ischaemia in defined populations.

Choice of material for above-knee femoropopliteal bypass graft

Autogenous saphenous vein is generally considered to be the best material for arterial bypass grafts below the inguinal ligament. Recent results have suggested that the advantage of vein over prosthesis is more pronounced in a distal situation, but it is not immediately apparent whether the difference is sufficient to justify a policy of using prosthesis for the initial above-knee graft to preserve the vein in case later surgery is required. An attempt has been made to answer this question. The literature has been reviewed to obtain estimates of the patency rates for grafts in different situations and a mathematical model has been set up using these figures to predict the outcome of different treatment policies. The model can be used to predict the result of alteration or inaccuracy in the data or to make use of the results of newly reported studies. The model predicts that the use of prosthesis for an initial graft will reduce the overall patency and substantially increase the requirement for reoperation, even if the present data give a substantial overestimate of the advantages of vein above the knee.